Augmented reality device

ABSTRACT

An augmented reality (AR) device includes a light source; a light source-moving delta robot on which the light source is mounted, the light source-moving delta robot being configured to change a traveling path of light emitted from the light source by adjusting at least one of a position or a slope of the light source in a three-dimensional (3D) space based on a movement of the light source-moving delta robot; a display device configured to generate a first image by modulating the light emitted from the light source; and a combiner configured to combine the first image generated by the display device with a second image, which is different from the first image and is received from an external source, and output a combined image.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2019-0138195, filed on Oct. 31, 2019, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND 1. Field

Example embodiments of the present disclosure relate to an augmentedreality (AR) device.

2. Description of Related Art

Recently, there have been increasing demands for augmented reality (AR)devices that allow users to visually recognize desired virtual imageswhile viewing real world scenes.

Generally, such an AR device includes a display device that generates avirtual image based on a particular signal and a combiner that allows auser to view the virtual image and a real world scene.

Examples of the display device may include a reflective display devicesuch as a liquid crystal on silicon display (LCoS), a digital micrometerdisplay (DMD), etc. Such a reflective display device may modulate lightreceived from a light source for each pixel to generate a virtual image.The reflective display device may include a flat-type structure. The ARdevice may need to further include a separate optical system (e.g., abeam splitter (BS)) that guides the light from the light source to thereflective display device. As a result, the volume of the AR deviceusing the reflective display device may increase.

The combiner may include a structure where the BS and the optical system(e.g., a lens, a mirror, etc.) are coupled with each other. However, asa viewing angle increases, the volume of the BS and the optical systemalso increases, resulting in an increase in the volume of the combiner.Moreover, research has been recently conducted on a holographic opticalelement (HOE) having complex optical characteristics that may be used inan augmented reality device as a combiner in a simple form.

The combiner using the HOE is configured to execute a function of aconcave mirror, such that a focus may be formed to create a virtualimage on a pupil position of a user. However, when the HOE is used as acombiner, an eye needs to be accurately positioned onto a very smallfocus area to view the virtual image, reducing an eye box that is animage-visible range (or a volume within which the user can place his orher pupil to experience the virtual image).

Meanwhile, delta robots are under research and development, these robotsbeing capable of performing various functions through precise andrepetitive movements in a small space. A delta robot may make high-speedrepetitive movements at a frequency of 75 Hz. Delta robots are appliedto surgical robots, robots for product assembly in the industry, etc.

SUMMARY

Provided is an AR device having an eye box that is expanded by using alight source-moving delta robot.

Provided is also an AR device including a light source-moving deltarobot, which substitutes for a display device.

According to an aspect of an example embodiment, there is provided anaugmented reality (AR) device including: a light source; a lightsource-moving delta robot on which the light source is mounted, thelight source-moving delta robot being configured to change a travelingpath of light emitted from the light source by adjusting at least one ofa position or a slope of the light source in a three-dimensional (3D)space based on a movement of the light source-moving delta robot; adisplay device configured to generate a first image by modulating thelight emitted from the light source; and a combiner configured tocombine the first image generated by the display device with a secondimage, which is different from the first image and is received from anexternal source, and output a combined image.

The light source-moving delta robot may include a fixed base; a stage onwhich the light source is mounted, the stage being spaced apart from thefixed base in a vertical direction; a plurality of leg portionsconfigured to interconnect the fixed base with the stage, each of theplurality of leg portions including at least one joint portionconfigured to execute a joint movement; and a driving unit configured toindependently provide a driving force to each of the plurality of legportions.

Each of the plurality of leg portions may include a first leg portionand a second leg portion, the first leg portion including at least onefirst joint portion and the second leg portion including at least onesecond joint portion.

The driving unit may be further configured to control the at least onefirst joint portion and the at least one second joint portion to move indirections different from each other.

The plurality of leg portions may include at least three leg portions.

The AR device may further include a sensor configured to sense aposition of a pupil of a user.

The AR device may further include a processor configured to controldriving of the light source-moving delta robot based on informationabout the position of the pupil of the user, the information beingprovided by the sensor.

The AR device may further include a reflective mirror provided betweenthe light source and the display device to reflect the light emittedfrom the light source toward the display device.

The light source may include an optical element array, in which aplurality of optical element packages are arranged in an array, each ofthe plurality of optical element packages including optical elements.

The combiner may include a holographic optical element.

According to an aspect of an example embodiment, there is provided anaugmented reality (AR) device including: a light source; a lightsource-moving delta robot on which the light source is mounted, thelight source-moving delta robot being configured to generate a firstimage by repeatedly adjusting at least one of a position or a slope ofthe light source in a three-dimensional (3D) space based on a movementof the light source-moving delta robot; and a combiner configured tocombine the first image generated by the light source-moving delta robotwith a second image, which is different from the first image and isreceived from an external source, and output a combined image.

The combiner may include a beam expander having a first area on which alight from the light source is incident and a second area on which thelight from the light source is combined with light from the externalsource, the beam expander configured to expand an area in which thelight from the light source is irradiated.

The beam expander may include a light guide plate including a firstsurface, on which the light from the light source is incident, and asecond surface opposite the first surface; an input grating provided inthe first area on the first surface or the second surface of the lightguide plate, the input grating being configured to diffract the lightfrom the light source to cause the diffracted light to travel by totalreflection inside the light guide plate; and an output grating providedin the second area on the first surface or the second surface of thelight guide plate, the output grating being configured to output thelight that has travelled inside the light guide plate by the inputgrating toward an outside of the light guide plate, the second areabeing spaced from the first area in a horizontal direction of the lightguide plate.

The beam expander may include a plurality of beam expanders that aresequentially arranged in a direction.

The AR device may further include an optical conversion lens providedbetween the light source and the combiner, the optical conversion lensbeing configured to direct the light from the light source toward thecombiner.

The output grating may be configured to output the light that hastravelled inside the light guide plate through the second surface.

The output grating may be configured to transmit light of the secondimage, based on which the first image is combined with the second imagein the second area of the beam expander and the combined image travelsthrough the second surface of the light guide plate.

The combiner may include a beam splitter including a first reflectingsurface that is inclined with respect to a traveling direction of lightfrom the light source, the first reflecting surface transmitting a firstpart of the light from the light source and reflecting a second part ofthe light from the light source; and an optical unit provided on atraveling path of light passing through the first reflecting surface,the optical unit including a second reflecting surface having a curve,and the second reflecting surface reflecting light passing through thebeam splitter to direct the reflected light toward the beam splitter.

The light source-moving delta robot may be configured to move along acurved trajectory to correct distortion of the first image caused by theoptical unit.

The AR device may further include a display device arranged on atraveling path of light of the second image, the display device beingconfigured to transmit the light of the second image, generate a thirdimage that is different from the first image and the second image, andprovide the second image and the third image to the combiner, whereinthe combiner is further configured to output a combined image obtainedby combining the first image, the second image, and the third image.

The combiner may include a beam splitter inclined with respect to atraveling direction of light from the light source, the beam splittertransmitting a first part of the light from the light source, reflectinga second part of the light from the light source, and transmitting lightof the third image from the display device and a part of the light ofthe second image; and a concave mirror provided on a traveling path oflight passing through the beam splitter from the light source, theconcave mirror reflecting the light passing through the beam splitter todirect the reflected light back toward the beam splitter.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain exampleembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 schematically illustrates an augmented reality (AR) deviceaccording to an example embodiment;

FIG. 2 schematically illustrates an example structure of a light sourceincluded in the AR device of FIG. 1 according to an example embodiment;

FIG. 3 schematically illustrates an example structure of a light sourceand a light source-moving delta robot of FIG. 1 according to an exampleembodiment;

FIG. 4 schematically illustrates an operation of a light source-movingdelta robot of FIG. 3 according to an example embodiment;

FIG. 5 schematically illustrates a structure of an AR device accordingto another example embodiment;

FIG. 6 schematically illustrates a structure of an AR device accordingto another example embodiment;

FIG. 7 is a plane view schematically illustrating an example structureof a light source included in the AR device of FIG. 1 according to anexample embodiment;

FIG. 8 schematically illustrates a structure of an AR device accordingto another example embodiment;

FIG. 9 schematically illustrates a structure of an AR device accordingto another example embodiment; and

FIG. 10 schematically illustrates a structure of an AR device accordingto another example embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout. In this regard,the example embodiments may have different forms and should not beconstrued as being limited to the descriptions set forth herein.Accordingly, the example embodiments are merely described below, byreferring to the figures, to explain aspects of the disclosure.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. Expressions such as “atleast one of,” when preceding a list of elements, modify the entire listof elements and do not modify the individual elements of the list. Forexample, the term “at least one of A and B” or “at least one of A or B”may be used to describe that three cases may exist: only A exists, bothA and B exist, and only B exists.

Hereinafter, an augmented reality (AR) device according to variousexample embodiments will be described in detail with reference to theaccompanying drawings. The AR device may be implemented in variousforms, and is not limited to the example embodiments described herein.Throughout the drawings, like reference numerals refer to like elements,and each element may be exaggerated in size for clarity and convenienceof a description.

Terms such as first, second, and the like may be used to describevarious elements, but the elements should not be limited to those terms.These terms may be used for the purpose of distinguishing one elementfrom another element. Any references to a singular element may includeplural elements unless expressly stated otherwise.

Further, two or more components which will be described later may beintegrated into a single component, and a single component which will beexplained later may be separated into two or more components. Moreover,each component which will be described may additionally perform some orall of a function executed by another component in addition to the mainfunction thereof. Some or all of the main function of each componentwhich will be explained may be carried out by another component. Eachcomponent may be implemented as hardware, software, or a combination ofboth.

Throughout the entirety of the specification of the disclosure, if it isassumed that a certain part includes a certain component, the term‘including’ means that a corresponding component may further includeother components unless a specific meaning opposed to the correspondingcomponent is written.

FIG. 1 schematically illustrates an AR device 1000 according to anexample embodiment. FIG. 2 schematically illustrates an examplestructure of a light source 100 included in the AR device 1000 of FIG. 1according to an example embodiment. FIG. 3 schematically illustrates anexample structure of the light source 100 and a light source-movingdelta robot 200 of FIG. 1 according to an example embodiment. FIG. 4schematically illustrates an operation of the light source-moving deltarobot 200 of FIG. 3 according to an example embodiment.

Referring to FIG. 1, the AR device 1000 may include a light source 100,a light source-moving delta robot 200 which has the light source 100mounted thereon and changes a traveling path of light emitted from thelight source 100 by adjusting at least one of a position or a slope ofthe light source 100 in a three-dimensional (3D) space throughthree-dimensional movement, a display device 300 which modulates lightfrom the light source 100 to generate a first image, and a combiner 400which combines the first image from the display device 300 with a secondimage that is different from the first image from an external source,and delivers a combined image to a user.

The light source 100 may emit monochromatic light of a visible region.For example, the light source 100 may include an optical element (e.g.,a light-emitting diode (LED)) which emits any one of red light, greenlight, or blue light. As illustrated in FIG. 2, the light source 100 mayinclude a plurality of optical elements including a first opticalelement R emitting red light, a second optical element G emitting greenlight, and a third optical element B emitting blue light. The pluralityof optical elements may be arranged on a substrate sub in a firstdirection and a second direction crossing the first direction. The firstoptical element R, the second optical element G, and the third opticalelement B, which emit light of different wavelengths, included in thelight source 100, may be driven independently of one another with timedifferences among them. Thus, the red light, the green light, and theblue light may be sequentially emitted from the light source 100, andthe first image formed by combinations of the red light, the greenlight, and the blue light may be delivered to a pupil 10 of the user.Each optical element included in the light source 100 may include alaser diode emitting a laser beam. In this case, light emitted from thelight source 100 may have coherence.

The light source-moving delta robot 200 has the light source 100 mountedthereon. Thus, the light source 100 may move together with movement ofthe light source-moving delta robot 200. As described below, an incidentangle of light from the light source 100 with respect to the displaydevice 300 may change with three-dimensional movement of the lightsource-moving delta robot 200.

Referring to FIG. 3, the light source-moving delta robot 200 may includea fixed base 201 and a stage 202 which is spaced vertically apart fromthe fixed base 201 and has mounted thereon the light source 100. Thelight source-moving delta robot 200 may include a plurality of first legportions 203 and a plurality of second leg portions 205 whichinterconnect the fixed base 201 and the stage 202. The plurality offirst and second leg portions 203 and 205 may include at least one firstjoint portion 204 and at least one second joint portion 206,respectively, to make a joint movement.

The joint movement may mean that members interconnected by the first andsecond joint portions 204 and 206 move in such a way that an anglerelative to each other changes. For example, the plurality of first andsecond leg portions 203 and 205 may include the first leg portion 203having a plurality of first joint portions 204 and the second legportion 205 having a plurality of second joint portions 206. In anexample, the first joint portion 204 may be formed between a first endportion of the first leg portion 203 and a first end portion of thestage 202 such that the joint movement may be made between the first legportion 203 and the stage 202. In another example, the first jointportion 204 may be formed in a middle portion of the first leg portion203 such that the joint movement may be made in a state where the firstleg portion 203 is divided into two regions. In still another example,the first joint portion 204 may be formed between a second end portionof the first leg portion 203 and a first end portion of the fixed base201 such that the joint movement may be made between the first legportion 203 and the fixed base 201. The second leg portion 205 may alsoinclude the plurality of second joint portions 206 in positionscorresponding to the first joint portions 204 of the first leg portion203 to make the joint movement in a plurality of regions. In this way,through the joint movement made among the fixed base 201, the first legportion 203, the second leg portion 205, and the stage 202, at least oneof a position or a slope of the stage 202 in the three-dimensional spacemay be adjusted. Moreover, the light source-moving delta robot 200 mayfurther include a third leg portion (not shown) interconnecting thefixed base 201 and the stage 202, and by using a combination of jointmovements of the first and second leg portions 203 and 205, and thethird leg portion, a change of the position and the slope of the stage202 in the 3D space may be further diversified.

The light source-moving delta robot 200 may further include a drivingportion (not shown) that independently delivers a driving force to eachof the plurality of first and second leg portions 203 and 205. Thedriving force from the driving unit may be delivered to the first jointportions 204 and the second joint portions 206 included in the pluralityof first and second leg portions 203 and 205. The driving unit mayinclude a plurality of piezoelectric elements connected to the pluralityof first and second leg portions 203 and 205, respectively.

The driving unit may control the first joint portions 204 and the secondleg portions 206 such that a moving direction of the first leg portion203 coincides with a moving direction of the second leg portion 205. Forexample, the driving unit may apply the same current to each of theplurality of piezoelectric elements included in the driving unit, suchthat the same driving force may be delivered to the plurality of firstand second leg portions 203 and 205. Thus, the plurality of first andsecond leg portions 203 and 205 may be driven by the same momentum. Forexample, as shown in FIG. 4, as the plurality of first and second legportions 203 and 205 are driven by the same momentum, the lightsource-moving delta robot 200 may make an upward-and-downward (orvertical) vibration movement with respect to a central line CL1 thatextends in an x-axis direction. In other words, the light source-movingdelta robot 200 may vibrate in a z-axis direction based on repeatedvertical movements of the plurality of first and second leg portions 203and 205, such that coordinates on the z axis of the 3D space of thelight source 100 mounted on the light source-moving delta robot 200 maybe changed.

The driving unit may control the first joint portions 204 and the secondleg portions 206, such that the moving direction of the first legportion 203 is different from the moving direction of the second legportion 205. For example, the driving unit may apply different currentsto each of the plurality of piezoelectric elements, such that differentdriving forces may be delivered to the plurality of first and second legportions 203 and 205. Thus, the plurality of first and second legportions 203 and 205 may be driven by different momentum. For example,as shown in FIG. 4, as the plurality of first and second leg portions203 and 205 are driven by different momentum, the light source-movingdelta robot 200 may make a horizontal vibration movement with respect toa central line CL2 that extends in the z-axis direction. In other words,the light source-moving delta robot 200 may vibrate in the x-axisdirection based on repeated horizontal movements of the plurality offirst and second leg portions 203 and 205, such that coordinates of thelight source 100 mounted on the light source-moving delta robot 200 onthe x axis on the 3D space may be changed. While the stage 202 isomitted in FIG. 4, this illustration is intended for convenience of adescription and the stage 202 may be included in the light source-movingdelta robot 200. The first leg portion 203 is illustrated as includingone first joint portion 204 and the second leg portion 205 isillustrated as including one second joint portion 206, but thisillustration is intended for convenience of a description and thedisclosure is not limited thereto.

As described above, the light source-moving delta robot 200 may furtherinclude a third leg portion (not shown) that is different from the firstleg portion 203 and the second leg portion 205. In this case, thedriving unit may further include a piezoelectric element connected withthe third leg portion. As the light source-moving delta robot 200vibrates in the z-axis direction and/or the x-axis direction, the lightsource-moving delta robot 200 may vibrate in the y-axis directiondepending on a current applying scheme of the driving unit. Thus,coordinates of the light source 100 mounted on the light source-movingdelta robot 200 on the y axis on the 3D space may be changed. Along withmovements of the first, second, and third leg portions, coordinates ofthe light source 100 mounted on the light source-moving delta robot 200on the x axis, the y axis, and/or the z axis on the 3D space may bechanged. Thus, at least one of the position or the slope of the lightsource 100 on the 3D space is adjusted, such that the traveling path oflight emitted from the light source 100 may be changed.

The display device 300 may generate the first image by modulating thelight from the light source 100. The first image may be referred to as avirtual image. The display device 300 may be a reflective displaydevice. For example, the display device 300 may include a silicon liquidcrystal display (LCoS) or a digital micrometer display (DMD). Thedisplay device 300 may include a plurality of pixels. Each pixel of thedisplay device 300 may generate the first image by adjusting the amountof light incident from the light source 100 based on a two-dimensional(2D) image signal from an external source. That is, the light from thelight source 100 may be modulated for each pixel in the display device300.

The combiner 400 may combine the first image generated by the displaydevice 300 with the second image from the external source and provide acombined image to the pupil 10 of the user. The second image may bereferred to as a virtual image. That is, the combiner 400 may combine areal image with the virtual image and provide a combined image to theuser.

The combiner 400 may include, for example, a holographic optical element(HOE). The HOE may include an interference pattern reproduced by lightfrom the light source 100. For example, the HOE may include a pluralityof interference patterns corresponding to light of different incidentangles. For example, the light source 100 may be arranged at a firstposition along with a movement of the light source-moving delta robot200, such that when light of a first incident angle is incident onto theHOE, a first interference pattern of the HOE may be reproduced to form avirtual image at a first convergence point. For example, the lightsource 100 may be arranged at a second position that is different fromthe first position along with a movement of the light source-movingdelta robot 200, such that when light of a second incident angle that isdifferent from the first incident angle is incident onto the HOE, asecond interference pattern of the HOE, which is different from thefirst interference pattern, may be reproduced to form a virtual image ata second convergence point. As such, the position or the slope of thelight source 100 on the 3D space may be changed along with the movementof the light source-moving delta robot 200, a convergence point may bediversified where the virtual image is formed. In this case, whencompared to using a fixed light source, an eye box of the AR device 1000may be enlarged.

As such, the combiner 400 may provide light 30 of the virtual image tothe user, and at the same time, pass light 20 of the real image from theexternal source therethrough to allow the light 20 to go to the pupil 10of the user. In this way, the combiner 400 may combine the real imagewith the virtual image and provide the combined image to the user.

FIG. 5 schematically illustrates a structure of an AR device 1010according to another example embodiment. The structure of the AR device1010 of FIG. 5 may be substantially the same as that of the AR device1000 of FIG. 1 except for a sensor 510 and a processor 610. Adescription will be made with reference to FIG. 5 by avoiding a repeateddescription made already with reference to FIG. 1.

Referring to FIG. 5, the AR device 1010 may include a light source 110,a light source-moving delta robot 210 having mounted thereon the lightsource 110 and make a three-dimensional movement, a display device 310which modulates light from the light source 110 to generate the firstimage, and a combiner 410 which combines the first image from thedisplay device 310 with the second image that is different from thefirst image from the external source, and delivers the combined image tothe user. The combiner 410 may combine light 21 of the real image fromthe external source with light 31 of the virtual image, emitted from thelight source 110 and modulated by the display device 310, and provide acombined image to a pupil 11 of the user. Moreover, the AR device 1010may further include a sensor 510 that senses a position of the user'spupil 11. The AR device 1010 may further include a processor 610 thatcontrols driving of the light source-moving delta robot 210 based oninformation about the position of the pupil 11 sensed by the sensor 510.

For example, the sensor 510 may transmit the information about theposition of the pupil 11 of the user to the processor 610. The processor610 may control driving of the light source-moving delta robot 210 basedon the obtained information about the position of the pupil 11 of theuser. The processor 610 may control driving of the light source-movingdelta robot 210 by controlling a driving unit included in the lightsource-moving delta robot 210. For example, when the user's pupil 11 ispositioned at the first convergence point, the processor 610 may drivethe light source-moving delta robot 210 to adjust at least one of theposition or the slope of the light source 110, such that the light fromthe light source 110 is directed toward the first convergence point. Forexample, when the user's pupil 11 is positioned at the secondconvergence point that is different from the first convergence point,the processor 610 may drive the light source-moving delta robot 210 toadjust at least one of the position or the slope of the light source110, such that the light from the light source 110 is directed towardthe second convergence point. In this way, by properly adjusting theposition of the light source 110 through the movement of the lightsource-moving delta robot 210 based on the position of the pupil 11,power consumed for generation of the virtual image may be minimized.

The processor 610 may include at least one hardware among a centralprocessing unit (CPU), a microprocessor, a graphic processing unit(GPU), application specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), or field programmable gate arrays(FPGAs), without being limited thereto.

FIG. 6 schematically illustrates an AR device 1020 according to stillanother example embodiment. The structure of the AR device 1020 of FIG.6 may be substantially the same as that of the AR device 1000 of FIG. 1except for a reflective mirror 720. A description will be made withreference to FIG. 6 by avoiding a repeated description made already withreference to FIG. 1.

Referring to FIG. 6, the AR device 1020 may include a light source 120,a light source-moving delta robot 220 which is a member having mountedthereon the light source 120 and make a three-dimensional movement, adisplay device 320 which modulates light from the light source 120 togenerate the first image, and a combiner 420 which combines the firstimage from the display device 320 with the second image that isdifferent from the first image from the external source, and deliversthe combined image to the user. The combiner 420 may combine light 22 ofthe real image from the external source with light 32 of the virtualimage, emitted from the light source 120 and modulated by the displaydevice 320, and provide a combined image to a pupil 12 of the user. TheAR device 1020 may further include a reflective mirror 720 that isprovided between the light source 120 and the display device 320 andcauses light from the light source 120 to be incident on the displaydevice 320 by changing a traveling direction of the light. Although notshown in FIG. 6, as described above with reference to FIG. 5, the ARdevice 1020 may further include a sensor (510 of FIG. 5) that senses theposition of the pupil 12 of the user and a processor (610 of FIG. 5)that controls driving of the light source-moving delta robot 210 basedon information about the position of the pupil 12 sensed by the sensor510.

The light from the light source 120 may be incident onto the displaydevice 320 in a state in which a traveling path of the light is changedby being reflected by the reflective mirror 720. Thus, even when thelight from the light source 120 is not immediately directed toward thedisplay device 320, the light from the light source 120 may be guidedtoward the display device 320. Hence, in the AR device 1020 includingthe reflective mirror 720, relative positions of the display device 320and the light source 120 with respect to each other may be configuredmore freely than in an AR device without a reflective mirror.

FIG. 7 is a plane view schematically illustrating an example structureof a light source 130 included in the AR device 1000 of FIG. 1.

Referring to FIG. 7, the light source 130 may include an optical elementarray where a plurality of optical element packages 131 including aplurality of optical elements R, G, and B are arranged in an array form.For example, one optical element package 131 may include a first opticalelement R emitting red light, a second optical element G emitting greenlight, and a third optical element B emitting blue light. The pluralityof optical element packages 131 may be regularly arranged on a substratesub in a horizontal direction and a vertical direction. By using thelight source 130 including the plurality of optical element packages131, the eye box of the AR device 1000 may be expanded while minimizinga movement of the light source-moving delta robot (200 of FIG. 1).

The first optical element R, the second optical element G, and the thirdoptical element B, which emit light of different wavelengths, includedin each of the optical element packages 131, may be driven independentlyof one another with time differences among them. Thus, the red light,the green light, and the blue light may be sequentially emitted from thelight source 130, and the first image formed by combinations of the redlight, the green light, and the blue light may be delivered to the pupil(10 of FIG. 1) of the user.

FIG. 8 schematically illustrates an AR device 1040 according to stillanother example embodiment.

Referring to FIG. 8, the AR device 1040 may include a light source 140,a light source-moving delta robot 240 which is a member having mountedthereon the light source 140 and generates the first image by repeatedlyadjusting at least one of the position or the slope of the light source140 in the 3D space through a three-dimensional movement, and a combiner440 which combines the first image with a second image, which isdifferent from the first image, from an external source and delivers acombined image to the user. Moreover, the AR device 1040 may furtherinclude an optical conversion lens 840 that directs the light from thelight source 140 toward the combiner 440 by refracting and collimatingthe light. The optical conversion lens 840 may be provided between thelight source 140 and the combiner 440.

The structures of the light source 140 and the light source-moving deltarobot 240 may be substantially the same as those of the light source 100and the light source-moving delta robot 200 of FIG. 1, respectively.

The light source-moving delta robot 240 may be driven at high speeds.Through repeated movements of the light source-moving delta robot 240based on high-speed driving, light emitted from the light source 140 mayform the first image, i.e., the virtual image. For example, the lightsource-moving delta robot 240 may be driven at high speeds at afrequency of 75 Hz. However, the disclosure is not limited thereto, andthe light source-moving delta robot 240 may be driven at high speeds ata frequency higher than 75 Hz. In this way, by generating the virtualimage merely with movement of the light source-moving delta robot 240,the AR device 1040 may not include a separate display device to generatethe virtual image.

The combiner 440 may include a beam expander which has a first area a1on which light from the light source 140 is incident and a second areaa2 in which the light from the light source 140 is combined with lightfrom an external source and combined light is delivered to the user. Byusing the beam expander, an irradiating area of light from the lightsource 140 is expanded. The beam expander may include a plurality ofbeam expanders that are sequentially arranged in a vertical direction.For example, the beam expander may include a first beam expander, asecond beam expander, and a third beam expander that are arranged in thevertical direction, as shown in FIG. 8. However, this is merely forconvenience of a description and the number of the beam expanderaccording to the disclosure is not limited thereto.

The first beam expander may include a first light guide plate 401 havinga first surface 401 a on which light of a first image from the lightsource 140 is incident and a second surface 401 b opposing the firstsurface 401 a, a first input grating 404 which is provided in the firstarea a1 on the first surface 401 a or the second surface 401 b anddiffracts the light from the light source 140 to travel by being totallyreflected inside the first light guide plate 401, and a first outputgrating 407 which is provided in the second area a2, which is spacedapart from the first area a1 in a horizontal direction of the firstlight guide plate 401, on the first surface 401 a or the second surface401 b, and diffracts and outputs the light traveling inside the firstlight guide plate 401 by the first input grating 404 in a directiontoward the outside of the first light guide plate 401. The first outputgrating 407 may output the light through the second surface 401 b of thefirst light guide plate 401.

The light source 140 may be arranged on the first area a1 such that thelight from the light source 140 is incident onto the first input grating404. The light arriving at the second area a2 by being totally reflectedinside the first light guide plate 401 through diffraction by the firstinput grating 404 may be output outwardly of the first light guide plate401 by the first output grating 407. In this case, an area of the firstoutput grating 407 may be greater than that of the first input grating404. Thus, the light traveling by being totally reflected inside thefirst light guide plate 401 through diffraction by the first inputgrating 404 may be output outwardly of the first light guide plate 401and an irradiation area of light from the light source 140 is enlargedby the first output grating 407.

The second beam expander and the third beam expander may havesubstantially the same structure as that of the first beam expander. Forexample, the second beam expander may include a second light guide plate402, a second input grating 405 provided in the first area a1 of thesecond light guide plate 402, and a second output grating 408 providedin the second area a2 of the second light guide plate 402. The thirdbeam expander may include a third light guide plate 403, a third inputgrating 406 provided in the first area a1 of the third light guide plate403, and a third output grating 409 provided in the second area a2 ofthe third light guide plate 403. As described above, the first beamexpander, the second beam expander, and the third beam expander may bearranged in the vertical direction. Thus, the first input grating 404,the second input grating 405, and the third input grating 406, providedin the first area a1, may be arranged in the vertical direction. Thefirst output grating 407, the second output grating 408, and the thirdinput grating 409, provided in the second area a2, may be arranged inthe vertical direction.

The first beam expander may increase an irradiation area of red lightfrom the light source 140. For example, the first input grating 404 andthe first output grating 407 included in the first beam expander may beconfigured to diffract only red light from the light from the lightsource 140. In this case, blue light and green light may pass throughthe first light guide plate 401 without being totally reflected insidethe first light guide plate 401 included in the first beam expander. Thesecond beam expander may increase an irradiation area of green lightfrom the light source 140. For example, the second input grating 405 andthe second output grating 408 included in the second beam expander maybe configured to diffract only green light from the light from the lightsource 140. In this case, red light and blue light may pass through thesecond light guide plate 402 without being totally reflected inside thesecond light guide plate 402 included in the second beam expander.Moreover, the third beam expander may increase an irradiation area ofblue light from the light source 140. For example, the third inputgrating 406 and the third output grating 409 included in the third beamexpander may be configured to diffract only blue light from the lightfrom the light source 140. In this case, red light and green light maypass through the third light guide plate 403 without being totallyreflected inside the third light guide plate 403 included in the thirdbeam expander.

The first output grating 407, the second output grating 408, and thethird output grating 409, arranged vertically in the second area a2, maypass light 24 of a real image from an external source therethrough. Thelight 24 of the real image from the external source may pass through thesecond area a2 of the first light guide plate 401, the second lightguide plate 402, and the third light guide plate 403. Thus, light 34 ofa virtual image from the plurality of output gratings 407, 408, and 409in the second area a2 may be combined with the light 24 of the realimage from the external source, which has passed through the second areaa2 of the first light guide plate 401, the second light guide plate 402,and the third light guide plate 403, such that combined light may bedelivered to a pupil 14 of the user.

The optical conversion lens 840 may be a convex lens. The opticalconversion lens 840 may be provided between the light source 140 and thecombiner 440. The optical conversion lens 840 may be provided betweenthe light source 140 and the first area a1 of the combiner 440. Lightfrom the light source 140 may be converted by the optical conversionlens 840 and travel to the combiner 440. For example, the light from thelight source 140 may be refracted and collimated by the opticalconversion lens 840 and travel toward the combiner 440 in the form ofparallel light. The light converted by the optical conversion lens 840may be called Fourier-transformed light. The light that isFourier-transformed by the optical conversion lens 840 may be incidentonto the first area a1 of the combiner 440. For example, the light thatis Fourier-transformed by the optical conversion lens 840 may beincident onto the first input grating 404, the second input grating 405,and the third input grating 406.

FIG. 9 schematically illustrates a structure of an AR device 1050according to another example embodiment. Referring to FIG. 9, the ARdevice 1050, like the AR device 1040 of FIG. 8, may include a lightsource 150, a light source-moving delta robot 250 which is a memberhaving mounted thereon the light source 150 and generates the firstimage by repeatedly adjusting at least one of the position or the slopeof the light source 150 in the 3D space through a three-dimensionalmovement, and a combiner 450 which combines the first image with asecond image, which is different from the first image, from an externalsource and delivers a combined image to the user. However, the structureof the combiner 450 of the AR device 1050 shown in FIG. 9 is differentfrom that of the combiner 440 of the AR device 1040 of FIG. 8, such thatthe following description will be made focusing on the combiner 450 withreference to FIG. 9.

Referring to FIG. 9, the combiner 450 may include a beam splitter 451.The beam splitter 451 may include a first incident surface 451 a onwhich light from the light source 150 is incident. Inside the beamsplitter 451, a first light-reflecting surface 451 c may be provided.The first light-reflecting surface 451 c may be inclined with respect tothe traveling direction of the light from the light source 150. Thefirst light-reflecting surface 451 c may pass therethrough a part of thelight incident from the light source 150 through the first incidentsurface 451 a, and reflect another part of the incident light. Forexample, the first light-reflecting surface 451 c may pass therethroughabout 50% of the incident light and reflect the other about 50% of theincident light. The combiner 450 may further include an optical unit 452including a second light-reflecting surface 452 a, provided in a lowerportion of the beam splitter 451. The light passing through the beamsplitter 451 may be incident onto the optical unit 452. The lightincident onto the optical unit 452 may be reflected by the secondlight-reflecting surface 452 a and may travel back toward the firstlight-reflecting surface 451 c of the beam splitter 451. A part of thelight incident back onto the first light-reflecting surface 451 c may bereflected and travel toward a pupil 15 of the user. Another part of thelight incident back onto the first light-reflecting surface 451 c maypass through the first light-reflecting surface 451 c. In this way, thefirst image may be provided to the user by using the light 35 emittedfrom the light source 150 and traveling toward the pupil 15 of the userthrough the combiner 450.

Moreover, the beam splitter 451 may include a second incident surface451 b onto which light of the real image from the external source isincident. The first incident surface 451 a and the second incidentsurface 451 b may be perpendicular to each other. The light of the realimage incident through the second incident surface 451 b from theexternal source may be incident onto the first light-reflecting surface451 c. The first light-reflecting surface 451 c may pass therethrough apart of the light 25 of the real image from the external source andreflect another part of the light 25. For example, the firstlight-reflecting surface 451 c may pass therethrough about 50% of theincident light and reflect the other about 50% of the incident light.The light passing through the first light-reflecting surface 451 c, fromthe light 25 of the real image from the external source, may traveltoward the pupil 15 of the user. In this way, the second image may beprovided to the user by using the light 25 incident from the externalsource and traveling toward the pupil 15 of the user through thecombiner 450.

As described above, the combiner 450 may combine the light of the firstimage from the light source 150 with the light of the second image fromthe external source and deliver the combined light to the user.

The second light-reflecting surface 452 a of the optical unit 452provided in the lower portion of the beam splitter 451 may be a surfacehaving a curve with respect to the traveling direction of the light. Forexample, the second light-reflecting surface 452 a may have a concavesurface with respect to the light from the light source 150. Thus, thesecond light-reflecting surface 452 a may function as a concave mirror.In this case, during reflection of the light by the secondlight-reflecting surface 452 a having a curve, distortion may occur dueto chromatic aberration in the first image. To correct such distortion,movement of the light source-moving delta robot 250 may be controlled.For example, when the light source-moving delta robot 250 is driven tomove along a curved trajectory 150 a, distortion of the light from thelight source 150 caused by the second light-reflecting surface 452 a maybe corrected. While it is illustrated in FIG. 9 that the lightsource-moving delta robot 250 moves along the curved trajectory 150 athat is downward convex, the form of the curved trajectory 150 a may bevarious without being limited to the illustration in FIG. 9. Forexample, the form of the curved trajectory 150 a may be upward convex.

FIG. 10 schematically illustrates an AR device 1060 according to stillanother example embodiment. Referring to FIG. 10, the AR device 1060,like the AR device 1040 of FIG. 8, may include a light source 160, alight source-moving delta robot 260 which is a member having mountedthereon the light source 160 and generates the first image by repeatedlyadjusting at least one of the position or the slope of the light source160 in the 3D space through a three-dimensional movement, and a combiner460 which combines the first image with a second image, which isdifferent from the first image, from an external source and delivers acombined image to the user. However, the structure of the combiner 460of the AR device 1060 shown in FIG. 10 is different from that of thecombiner 440 of the AR device 1040 of FIG. 8. The AR device 1060 may bedifferent in terms of a structure from the AR device 1040 of FIG. 8 inthat the AR device 1060 further includes a display device 360 thatgenerates a third image and delivers the third image to the combiner440. Thus, the following description will be focused on the combiner 460and the display device 360.

Referring to FIG. 10, the combiner 460 may include a beam splitter 461.For example, the beam splitter 461 may be a dichroic mirror that passesa part of light therethrough and reflects another part of the light. Thebeam splitter 461 may be inclined with respect to the travelingdirection of the light. The light source 160 may be provided in a firstside direction of the beam splitter 461. The beam splitter 461 may passtherethrough a part of light from the light source 160 provided in thefirst side direction and reflect another part of the light. For example,the beam splitter 461 may pass therethrough about 50% of the incidentlight and reflect the other about 50% of the incident light. Thecombiner 460 may further include an optical unit 462 including areflecting surface, provided in a lower portion of the beam splitter461. The optical unit 462 may be provided in the lower portion of thebeam splitter 461, such that the optical unit 462 may be provided on atraveling path of the light from the light source 160, which has passedthrough the beam splitter 461. The optical unit 462 may be, for example,a concave mirror. The light which is emitted from the light source 160and passes through the beam splitter 461 may be incident onto theoptical unit 462 provided in the lower portion of the beam splitter 461.The light incident onto the optical unit 462 may be reflected by thereflecting surface of the optical unit 462 and may travel back towardthe beam splitter 461. A part of the light incident back onto the beamsplitter 461 may be reflected and travel toward a pupil 16 of the user.Another part of the light incident back onto the beam splitter 461 maypass through the beam splitter 461. In this way, the first image may beprovided to the user by the light 36 emitted from the light source 160and traveling toward the pupil 16 of the user through the combiner 460.

Light 26 of the real image from the external source in a second sidedirection of the combiner 460 may be incident onto the combiner 460. Thefirst side direction and the second side direction may be perpendicularto each other. The light 26 of the real image from the external source,which is incident in the second side direction, may be incident onto thebeam splitter 461. The beam splitter 461 may pass therethrough a part ofthe light 26 of the real image from the external source and reflectanother part of the light 26. For example, the beam splitter 461 maypass therethrough about 50% of the incident light and reflect the otherabout 50% of the incident light. The light passing through the beamsplitter 461, from the light 26 of the real image from the externalsource, may travel toward the pupil 16 of the user. In this way, thesecond image may be provided to the user by the light 26 incident fromthe external source and traveling toward the pupil 16 of the userthrough the combiner 460.

Moreover, the AR device 1060 may further include the display device 360that is arranged in the second side direction of the combiner 460 andgenerates the third image that is different from the first and secondimages and delivers the third image to the combiner 460. For example,the display device 360 may include an organic light emitting diode(OLED). The light of the third image generated by the display device 360may be incident onto the beam splitter 461. A part of the light of thethird image may pass through the beam splitter 461 and travel toward thepupil 16 of the user. The display device 360 may be arranged on thetraveling path of the light 26 of the real image from the externalsource. The display device 360 may pass therethrough the light 26 of thereal image from the external source. For example, the display device 360may include a transparent organic light-emitting device. Thus, light 46of the third image generated by the display device 360 and the light 26of the real image from the external source, which has passed through thecombiner 460, may be combined, such that the combined light may passthrough the beam splitter 461 to travel toward the pupil 16 of the user.

In this way, the light 36 of the first image generated by the lightsource 160, the light 26 of the second image (or real image) from theexternal source, and the light 46 of the third image generated by thedisplay device 360 may be combined by the combiner 460, and the combinedlight may be delivered to the user. In this case, both of the firstimage and the third image may be virtual images. The first image may bea virtual image generated by high-speed driving of the lightsource-moving delta robot 260, and may be the virtual image in ahigh-resolution area among desired virtual images. The third image maybe a virtual image generated by the display device 360, and may be thevirtual image in a low-resolution area among the desired virtual images.As such, a scheme to generate virtual images of two types havingdifferent resolutions and combine the virtual images may be referred toas a Foveated scheme. By using the Foveated scheme, a virtual image of ahigh display quality may be provided to the user, while reducing a datathroughput for generating the virtual image.

Various example embodiments of the disclosure may provide an AR devicehaving an eye box that is enlarged by using a light source-moving deltarobot.

Various example embodiments of the disclosure may also provide an ARdevice including a light source-moving delta robot, which substitutes adisplay device.

It should be understood that the example embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments of the disclosure. While one or moreembodiments have been described with reference to the figures, it willbe understood by those of ordinary skill in the art that various changesin form and details may be made therein without departing from thespirit and scope as defined by the following claims.

What is claimed is:
 1. An augmented reality (AR) device comprising: alight source; a light source-moving delta robot on which the lightsource is mounted, the light source-moving delta robot being configuredto change a traveling path of light emitted from the light source byadjusting at least one of a position or a slope of the light source in athree-dimensional (3D) space based on a movement of the lightsource-moving delta robot; a display device configured to generate afirst image by modulating the light emitted from the light source; and acombiner configured to combine the first image generated by the displaydevice with a second image, which is different from the first image andis received from an external source, and output a combined image.
 2. TheAR device of claim 1, wherein the light source-moving delta robotcomprises: a fixed base; a stage on which the light source is mounted,the stage being spaced apart from the fixed base in a verticaldirection; a plurality of leg portions interconnecting the fixed basewith the stage, each of the plurality of leg portions comprising atleast one joint portion configured to execute a joint movement; and adriving unit configured to independently provide a driving force to eachof the plurality of leg portions.
 3. The AR device of claim 2, whereineach of the plurality of leg portions comprises a first leg portion anda second leg portion, the first leg portion comprising at least onefirst joint portion and the second leg portion comprising at least onesecond joint portion.
 4. The AR device of claim 3, wherein the drivingunit is further configured to control the at least one first jointportion and the at least one second joint portion to move in directionsdifferent from each other.
 5. The AR device of claim 2, wherein theplurality of leg portions comprise at least three leg portions.
 6. TheAR device of claim 1, further comprising a sensor configured to sense aposition of a pupil of a user.
 7. The AR device of claim 6, furthercomprising a processor configured to control driving of the lightsource-moving delta robot based on information about the position of thepupil of the user, the information being provided by the sensor.
 8. TheAR device of claim 1, further comprising a reflective mirror providedbetween the light source and the display device to reflect the lightemitted from the light source toward the display device.
 9. The ARdevice of claim 1, wherein the light source comprises an optical elementarray, in which a plurality of optical element packages are arranged inan array, each of the plurality of optical element packages comprisingoptical elements.
 10. The AR device of claim 1, wherein the combinercomprises a holographic optical element.
 11. An augmented reality (AR)device comprising: a light source; a light source-moving delta robot onwhich the light source is mounted, the light source-moving delta robotbeing configured to generate a first image by repeatedly adjusting atleast one of a position or a slope of the light source in athree-dimensional (3D) space based on a movement of the lightsource-moving delta robot; and a combiner configured to combine thefirst image generated by the light source-moving delta robot with asecond image, which is different from the first image and is receivedfrom an external source, and output a combined image.
 12. The AR deviceof claim 11, wherein the combiner comprises a beam expander having afirst area on which a light from the light source is incident and asecond area on which the light from the light source is combined withlight from the external source, the beam expander configured to expandan area in which the light from the light source is irradiated.
 13. TheAR device of claim 12, wherein the beam expander comprises: a lightguide plate comprising a first surface on which the light from the lightsource is incident, and a second surface opposite the first surface; aninput grating provided in the first area on the first surface or thesecond surface of the light guide plate, the input grating beingconfigured to diffract the light from the light source to cause thediffracted light to travel by total reflection inside the light guideplate; and an output grating provided in the second area on the firstsurface or the second surface of the light guide plate, the outputgrating being configured to output the light that has travelled insidethe light guide plate by the input grating toward an outside of thelight guide plate, and the second area being spaced apart from the firstarea in a horizontal direction of the light guide plate.
 14. The ARdevice of claim 12, wherein the beam expander includes a plurality ofbeam expanders that are sequentially arranged in a direction.
 15. The ARdevice of claim 12, further comprising an optical conversion lensprovided between the light source and the combiner, the opticalconversion lens being configured to direct the light from the lightsource toward the combiner.
 16. The AR device of claim 13, wherein theoutput grating is configured to output the light that has travelledinside the light guide plate through the second surface.
 17. The ARdevice of claim 13, wherein the output grating is configured to transmitlight of the second image, based on which the first image is combinedwith the second image in the second area of the beam expander and thecombined image travels through the second surface of the light guideplate.
 18. The AR device of claim 11, wherein the combiner comprises: abeam splitter comprising a first reflecting surface that is inclinedwith respect to a traveling direction of light from the light source,the first reflecting surface transmitting a first part of the light fromthe light source and reflecting a second part of the light from thelight source; and an optical unit provided on a traveling path of lightpassing through the first reflecting surface, the optical unitcomprising a second reflecting surface having a curve, and the secondreflecting surface reflecting light passing through the beam splitter todirect the reflected light toward the beam splitter.
 19. The AR deviceof claim 18, wherein the light source-moving delta robot is furtherconfigured to move along a curved trajectory to correct distortion ofthe first image caused by the optical unit.
 20. The AR device of claim11, further comprising a display device arranged on a traveling path oflight of the second image, the display device being configured totransmit the light of the second image, generate a third image that isdifferent from the first image and the second image, and provide thesecond image and the third image to the combiner, wherein the combineris further configured to output a combined image obtained by combiningthe first image, the second image, and the third image.
 21. The ARdevice of claim 20, wherein the combiner comprises: a beam splitterinclined with respect to a traveling direction of light from the lightsource, the beam splitter transmitting a first part of the light fromthe light source, reflecting a second part of the light from the lightsource, and transmitting light of the third image from the displaydevice and a part of the light of the second image; and a concave mirrorprovided on a traveling path of light passing through the beam splitterfrom the light source, the concave mirror reflecting the light passingthrough the beam splitter to direct the reflected light back toward thebeam splitter.